Conventional wisdom suggests that the future of coal-fired power generation—from which the United States derives roughly one-half of its power—depends in no small part on the realization of geologic sequestration of carbon emissions in underground formations (for more on this, see Climate Change Deskbook §1.2.3.1.2). Two recent proposals by the U.S. Environmental Protection Agency (EPA) bring this issue to the fore: the Agency’s prevention of significant deterioration (PSD) tailoring rule and its geologic sequestration well rule.

EPA’s proposed PSD tailoring rule, 74 Fed. Reg. 55292 (Oct. 27, 2009), if taken to its logical extension and finalized, would subject some 14, of the greatest emitting sources of carbon to new control technologies. This rulemaking begs the question of what control technology is best for controlling carbon dioxide (CO2) emissions from coal-fired power plants. Some environmental groups argue that the best control technology for coal-fired plants is to switch their fuel to natural gas, believing that the Agency can compel fuel switches pursuant to its authority to select control technologies under the Clean Air Act. Others think such a command would be too drastic and falls beyond the realm of what control technology is intended to be. The control technology refuge for coal-fired plants might lie in the geologic sequestration of captured carbon.